The present invention relates to motor driven surgical instruments; and specifically to mechanisms for releasably attaching a variety of different tool bits to the surgical instrument.
Orthopedic and neurological surgeons frequently use a power driven surgical instrument to cut, shape and drill into bone. Such an instrument utilizes a small pneumatically driven motor contained in a cylindrical housing which is held by the surgeon during use. A hose from the source of compressed air attaches to one end of housing. A tool bit is received by a fitting at the other end of the housing and is rotated by the motor when compressed air is applied to the instrument.
A wide variety of different shaped and sized tool bits are available for drilling into, cutting, and shaping bone as needed during a surgical procedure. Thus, the surgical instrument must be able to accept various kinds and sizes of tool bits.
One common surgical instrument of this type used a collet to connect an end of the tool bit shaft to the spindle of the motor. This connection required a special collet wrench in order to replace the tool bit. In addition, the various tool bits had different sized shafts thus requiring different size collets. The need for corresponding sized collets and wenches not only made tool replacement time consuming and cumbersome, it required that additional items be stocked in the operating room. Further because a sterile environment was necessary for the surgical procedure, the different collets and wrenches have to be sterilized between the procedures.